In 1989, Dr. Krämer completed his Ph.D. at the University of Cologne, Germany, where he worked with Dr. Benno Mülller-Hill on DNA looping in the lac operon. As a postdoctoral fellow in the lab of Dr. Larry Zipursky at UCLA, he studied cell-cell interactions during neuronal differentiation in the compound eye of Drosophila. In 1993, he joined UT Southwestern Medical Center at Dallas as an Assistant Professor in Cell Biology and Neuroscience.



Graduate School
Cologne University (1989), Genetics

Research Interest

  • Cell signaling in the Drosophila eye
  • Drosophila genetics
  • Endocytic trafficking in development
  • Membrane trafficking and autophagy


Featured Publications LegendFeatured Publications

Neuralized: regulating notch by putting away delta.
Krämer H Dev. Cell 2001 Dec 1 6 725-6
The Golgi-associated hook3 protein is a member of a novel family of microtubule-binding proteins.
Walenta JH, Didier AJ, Liu X, Krämer H J. Cell Biol. 2001 Mar 152 5 923-34
Drosophila endosomal proteins hook and deep orange regulate synapse size but not synaptic vesicle recycling.
Narayanan R, Krämer H, Ramaswami M J. Neurobiol. 2000 Nov 45 2 105-19
A role for the deep orange and carnation eye color genes in lysosomal delivery in Drosophila.
Sevrioukov EA, He JP, Moghrabi N, Sunio A, Krämer H Mol. Cell 1999 Oct 4 4 479-86
Genetic dissection of endocytic trafficking in Drosophila using a horseradish peroxidase-bride of sevenless chimera: hook is required for normal maturation of multivesicular endosomes.
Sunio A, Metcalf AB, Krämer H Mol. Biol. Cell 1999 Apr 10 4 847-59
Mutations in the Drosophila hook gene inhibit endocytosis of the boss transmembrane ligand into multivesicular bodies.
Krämer H, Phistry M J. Cell Biol. 1996 Jun 133 6 1205-15
Extracellular domain of the boss transmembrane ligand acts as an antagonist of the sev receptor.
Hart AC, Krämer H, Zipursky SL Nature 1993 Feb 361 6414 732-6
The bride of sevenless and sevenless interaction: internalization of a transmembrane ligand.
Cagan RL, Krämer H, Hart AC, Zipursky SL Cell 1992 May 69 3 393-9
Interaction of bride of sevenless membrane-bound ligand and the sevenless tyrosine-kinase receptor.
Krämer H, Cagan RL, Zipursky SL Nature 1991 Jul 352 6332 207-12

Honors & Awards

  • American Cancer Society Postdoctoral Fellowship
  • EMBO Long Term Fellowship
  • Predoctoral Fellowship in the Fritz-Thyssen-Graduierten-Kolleg